Is there a difference between lepè and tonton. Can I call my future father-in-law by either of these names?

lepè sounds like he's old.
tonton could be an old guy, a person of very short stature, or a name that everyone calls him by... such as Tonton Max, Tonton Clovil, etc....
If everyone calls him lepè, then you can call him that.  Same thing as tonton too.
Otherwise call him Mesye intèl (intèl meaning such and such)
Or ask him, " Kijan pou m rele w?" (How should I call you?)

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